Cooling device



Dec. 15, 1936. w BUSCHBECK 2,064,372

COOLING DEVICE Filed Jan. 13, 1932 INVENTOR WEBNER BU CHBECK BY ATTORNEY Patented Dec. 15, 1936 UNITED STATES 2,064,372 COOLING DEVICE Werner Buschbeck, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H., Berlin, Germany, a corporation of Germany Application January 13, 1932, Serial No. 586,369 In Germany January 14, 1931 4 Claims.

This invention relates to cooling devices and in particular to water circulating means for the cooling of radio apparatus at high frequency potential to earth.

In radio or high frequency work it is often necessary to cool by water circulating means of the apparatus carrying a high specific load. The beginning and end of the water conduit usually is at ground potential. If the apparatus to be cooled present a potential which is substantially higher than the ground potential the losses or fall of potential in case of direct current and of low frequency alternating current may be kept at any desired low potential value by the insertion of a sufficiently long Water conduit or path, which provides an adequately high leak resistance. The situation, is different whenever radio or high frequency current is dealt with in a circuit.

The invention will best be understood by referring to the accompanying drawing in which Figure 1 shows a diagrammatic circuit arrangement of the distributed capacity of a water column,

Figure la shows a curve of the constant potential gradient relative to ground,

Figure 2 shows a straight water conduit with a capacity arrangement,

Figure 3 shows a straight water conduit with an inductance arrangement.

Referring now in detail to the drawing,

Figure 1 indicates how the distributed capacity of a column of water to ground results in a rapid fall of potential along the column of water. This fall of potential may be calculated, for instance, by approximately the laws applying to a pure capacity-resistance circuit. It will readily be seen the potential drops very rapidly along the column of water so that as soon as a certain length of Water column (which in practice is usually rather short) has been exceeded, the same can not be further diminished by increasing the conduit of the water.

Now according to this invention the effective electrical resistance of the circuit is gradually increased by changing the length of the water column so that the potential along the latter is regulated to result in a uniform fall of potential. This could be accomplished, by arranging the Water column in a discontinuous manner by pieces of pipe P having a larger outside diameter than the conduit and surrounding the water conduit which is connected by means of a capacitive potentiometer scheme insuring constant potential gradations relative to earth as shown in Figure -2.

In another modification which is a still better and simpler manner of producing a uniform drop of potential, there is provided a continuous metallic inductance coil wrapped around the water conduit of non-conducting material as shown in Fig. 3. In this arrangement it is desirable that the working wave length be greater than the natural wave of the coil L. As the Water conduit or pipe consists of non-conducting material, the wire of the coil L can be wrapped directly upon this pipe without additional insulation or spacing means. With the water column or the resistance corresponding thereto, coil L is electrically connected by means of the distributed capacity occurring between the water column and the coil L. In other words, there is formed between the high potential point and ground an electrical resistance arranged parallel to the inductance coil L which is electrically connected in shunt at the high potential point and ground. Between the parallel arranged resistance and inductance there is formed what is an equivalent to a group of serially connected capacitors thus insuring a uniform potential drop from the apparatus and ground. Inasmuch as the high frequency and the extremely high water resistance, the resistance of the capacities is small compared therewith. The serially connected capacitors formed by the distributed capacity between the water column resistance and inductance coil L can be disregarded and considered as short-circuited or joined by a group of conductors. What follows therefrom is that in the presence of a uniform voltage distribution across the coil, also the voltage distribution across the equivalent resistance must be uniform. Inasmuch as the length of the coil may be chosen at will also the voltage may be divided over any desired length of the water column so that the drop or loss in the water column can be diminished at will.

In both of these arrangements the high potential end of the high frequency element is connected at the top of the terminal end opposite the ground terminal so that the drop in potential takes place between the top terminal point and ground g.

It will now be seen that the effective electrical inductance of the coil L provides a high reactance path at high or radio frequencies from the terminals of the radio apparatus to be cooled by the circulation of water.

potential terminal and ground."

I claim: 7 r I 1. Water cooling arrangement for high-fre-' quency apparatus to be operated at high frequencies, comprising a straight water supply tube of non-conducting material for cooling said apparatus, a coil surrounding said water supply tube for causing the ambient potential of said water supply tubetofall at a uniform rate.

2. Water cooling arrangement for high-'frequencyapparatus to be operated at high f-r e-f 'lquencies, comprising a straight water supply tube .of nonconducting material forcooling said apparatus, and an inductance" coil; wrapped around said supply tube, -the upper end of said;

coil being connected to the high potentiahtera minal of said high frequency apparatus and the lowerend of said coil grounded soas to provide a uniform drop of potential between said high 3. Water supplyand cooling arrangement for apparatus operated at high frequencies, a substantially straight non-conducting waterfsupply tube for cooling said apparatus, an inductance coil Wrapped around said tube, the upper end of said coil being connected to the high potential end of said high frequency apparatus, the lower'end of said coil being grounded so as to provide a uniform drop of potential between said apparatus and. ground.

4. Water supply and cooling arrangement for apparatus operated at high frequencies, a subpotential so as to provide a uniform drop of potential between said high frequency apparatus .andground.

WERNER BUSCHBECK. 

